Development of an extremely thin-wall straw tracker operational in vacuum – The COMET straw tracker system
Development of an extremely thin-wall straw tracker operational in vacuum – The COMET straw tracker system
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DOI：
10.1016/j.nima.2016.06.082
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发表时间：
2017-02
影响因子：
1.4
通讯作者：
H. Nishiguchi;P. Evtoukhovitch;Y. Fujii;E. Hamada;S. Mihara;A. Moiseenko;K. Noguchi;K. Oishi;S. Tanaka;J. Tojo;Z. Tsamalaidze;N. Tsverava;K. Ueno;A. Volkov
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文献类型：
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作者：
H. Nishiguchi;P. Evtoukhovitch;Y. Fujii;E. Hamada;S. Mihara;A. Moiseenko;K. Noguchi;K. Oishi;S. Tanaka;J. Tojo;Z. Tsamalaidze;N. Tsverava;K. Ueno;A. Volkov
J-PARC的彗星实验旨在寻找介子原子中介子到电子转换的轻子味违反过程，μ-e转换的分支比灵敏度优于10−16，比目前的极限好4个数量级，以探索超出标准模型的大多数良好激励理论模型预测的参数区域。对这种灵敏度的需要对探测器的发展提出了几个严格的要求。实验要求检测105mev的单色电子，该动量区域的动量分辨率主要受多重散射效应的限制。因此，我们需要非常轻的材料探测器，以便在100 MeV区域获得优于2%的优异动量分辨率。为了满足这一要求，采用一种极轻的操作真空材料研制了薄壁秸秆管平面跟踪器。COMET秸秆跟踪器由直径9.8 mm、长度大于1 m的秸秆管、20 μm厚的Mylar箔和70 nm厚的铝沉积组成。目前正在利用超声波焊接技术研制更薄更小的吸管，厚度为12 μm，直径为5 mm。
The COMET experiment at J-PARC aims to search for a lepton-flavour violating process of muon to electron conversion in a muonic atom,μ-e conversion, with a branching-ratio sensitivity of better than 10−16, 4 orders of magnitude better than the present limit, in order to explore the parameter region predicted by most of well-motivated theoretical models beyond the Standard Model. The need for this sensitivity places several stringent requirements on the detector development. The experiment requires to detect the monochromatic electron of 105 MeV, the momentum resolution is primarily limited by the multiple scattering effect for this momentum region. Thus we need the very light material detector in order to achieve an excellent momentum resolution, better than 2%, for 100 MeV region. In order to fulfil such a requirement, the thin-wall straw-tube planar tracker has been developed by anextremely lightmaterial which is operational invacuum. The COMET straw tracker consists of 9.8 mm diameter straw tube, longer than 1 m length, with 20-μm-thick Mylar foil and 70-nm-thick aluminium deposition. Currently even thinner and smaller, 12 μm thick and 5 mm diameter, straw is under development by the ultrasonic welding technique.